Leaves are the primary food‐producing organs for a plant that carry out photosynthesis and contribute to biomass and grain yield. Leaf senescence is a developmentally regulated physiological process but early leaf senescence is known to negatively affect plant yield. The cuticle is an outer waxy protective layer on the leaf surface which protects plants from pathogens attack as well as dehydration. Our understanding of the molecular mechanisms underlying cuticle development and leaf senescence is still immature. The present study reports the role of the DEGENERATED PANICLE AND PARTIAL STERILITY 1 (DPS1) gene encoding a cystathionine β‐synthase (CBS) domain‐containing protein in cuticle development and leaf senescence in rice. The dps1 loss‐of‐function mutant showed leaf senescence phenotype with twisted leaves, significantly reduced chlorophyll content and degenerated chloroplasts characterized by a reduced number of starch granules and an abundance of osmiophilic bodies. Furthermore, dps1 leaves displayed defective cuticle development, reduced wax and cutin compounds, and lower relative water content as compared with wild type. Physiological assays showed significantly higher accumulation of reactive oxygen species (ROS) accompanied by enhanced DNA fragmentation in dps1 leaves, which could be associated with chloroplast degeneration and defective cuticle development. Transcriptome analysis revealed altered expression of several critical genes related to photosynthesis and wax/cutin pathway. This study revealed a crucial role of DPS1 in regulating leaf cuticle development and senescence by affecting the expression of several genes. Thus, a moderate expression of DPS1 is necessary for better plant growth and productivity.

中文翻译：

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DPS1调节水稻的表皮发育和叶片衰老

叶片是植物的主要食物生产器官，能够进行光合作用并有助于生物量和谷物产量。叶片衰老是发育调控的生理过程，但已知早期叶片衰老会对植物产量产生负面影响。角质层是叶片表面的蜡质外保护层，可保护植物免受病原体侵袭和脱水。我们对表皮发育和叶片衰老的分子机制的了解仍不成熟。本研究报道了编码半胱氨酸β-合酶（CBS）结构域蛋白的简并部分不育1（DPS1）基因在水稻表皮发育和叶片衰老中的作用。该DPS1功能丧失型突变体表现出叶片扭曲的叶片衰老表型，叶绿素含量显着降低，叶绿体退化，其特征是淀粉粒数量减少和嗜亲性体丰富。此外，与野生型相比，dps1叶片显示出不良的角质层发育，减少的蜡和角质化合物以及较低的相对含水量。生理测定显示dps1中活性氧（ROS）的积累显着增加，同时DNA断裂增强叶片，可能与叶绿体变性和角质层发育不良有关。转录组分析显示与光合作用和蜡/角质蛋白途径相关的几个关键基因的表达发生了改变。这项研究揭示了DPS1通过影响几种基因的表达在调节叶表皮发育和衰老中的关键作用。因此，DPS1的适度表达对于更好的植物生长和生产力是必要的。